From the WebMD Archives
May 1, 2002 — There is an increasingly popular belief that the rise in allergies and asthma is partly attributable to the fact that children are less frequently exposed to viral infections early in life. A Danish study says this is not so.
Mads Melbye, MD, DMSc, and colleagues from the Statens Serum Institut in Copenhagen looked at nearly 900 women. Because Denmark maintains a comprehensive national database for all citizens, the researchers had access to detailed medical information for each of the women from her date of birth.
Their complete report appears in the current issue of Thorax.
They looked specifically at each women’s childhood history of various viral infections — measles, rubella (German measles), chickenpox, and mumps — and at whether they now had allergies to 11 common inhaled substances including dog and cat dander, grass, dust mites, and mold.
They found that the more infections a woman had acquired before age 2, the greater her risk of having developed allergies.
According to the researchers, these findings directly contradict the so-called “hygiene hypothesis” that says our increasingly clean and virus-free living environment is somehow weakening us — making us prone to allergies and other health woes.
